The present disclosure relates to rheological methods for measuring crosslinking, flame performance, chemical retardance, mechanical properties, or other characteristics of a crosslinked polycarbonate. These methods are particularly useful with polycarbonates that have been crosslinked by exposure to ultraviolet light.
Crosslinking of polymeric chains is a common method for modifying polymers because of its influence on mechanical properties, mobility, solubility, and diffusion. Potential benefits included improved mechanical and thermal properties as well as superior chemical and flame retardance. These attributes are desirable in applications ranging from automotive to telecommunications to consumer electronics and other fields.
Crosslinks can be formed by chemical reactions initiated by, for example, heating or irradiation. Desirably, covalent crosslinking bonds are formed, since such bonds are mechanically and thermally stable, and thus are harder to break. The morphology of the crosslinks can affect the properties and features of the crosslinked polymer. It would be desirable to be able to quantify the amount of crosslinking in a crosslinked polymer, and/or to be able to predict the properties of the crosslinked polymer based on the amount of crosslinking.